1. Field of the Invention
This application relates generally to the filtering of liquids in containers, and, more specifically, to an improved liquid filter apparatus.
2. Description of the Related Art
Cooking oil is extensively used in the food industry to cook comestibles. Animal fat, vegetable oil or other suitable material may be used as the cooking material. The term “cooking oil” is used herein to designate any such material.
Frying is frequently accomplished in relatively deep containers with the comestible to be cooked immersed in the cooking oil. In cases where quantities of food are regularly cooked in such a manner, the cooking oil becomes contaminated with various particles of food or other impurities. Food particles become charred from continued exposure to temperatures used in frying operations. Such charred food particles produce an odor and adversely affect the taste of foods cooked therein. Degradation of the cooking oil by suspended contaminants may also have a negative effect on the health of the consumer.
To beneficially control free fatty acids, polymers, and other undesirable components in the cooking oil, suspended particles of comestibles should be removed from the cooking oil. Wire mesh strainers have been long known and used to remove particulate matter from cooking oil. Strainers have not been effective to remove sufficient particulate matter to provide particulate-free cooking oil, and only slightly prolong the usefulness of the cooking oil.
Many conventional systems for filtering cooking oil require that the cooking operation be interrupted for the filtering procedure to be accomplished. The cooking oil is typically removed from the fryer container, and filtered and returned to the fryer, or, alternatively is replaced. Continuous filtering systems allow filtering during the frying operation.
U.S. Pat. No. 2,635,527 to Overbeck discloses a deep frying strainer to be located at the bottom of the cooking oil container to strain food particles from cooking oil as the strainer is lifted from the container. Although beneficial to remove some particulate matter, the invention disclosed does not effectively remove smaller particulate contaminants.
U.S. Pat. No. Re. 34,636, reissued on Jun. 14, 1994, to the present inventor, describes a cooking oil filter apparatus which can be used to effectively remove particulates from the cooking oil. Cooking oil is drawn through wire mesh screens by applying suction at the filter interior. As the cooking oil is drawn through the wire mesh screens, the screen serves to remove particulates from the cooking oil. The particulate-free cooking oil is then drawn into an outlet and drawn through the tank to a pump. The pump passes the cooking oil back into the tank.
U.S. Pat. No. 5,404,799, issued on Apr. 11, 1995, and U.S. Pat. No. 5,486,370, issued on Jan. 23, 1996, both to the present inventor, describe cooking oil filter apparatuses and methods which can be used to effectively remove particulates from the cooking oil.
U.S. Pat. No. 2,760,641 to Miles, et al. discloses a portable filter apparatus for use in cleaning cooking oil or other liquids. Contaminated cooking oil is first drained from the cooking reservoir into a draw-off container. The filter is then submerged in the oil in the draw-off container. The oil is then pumped by the pump motor through the filter and pump. The pump discharges the oil through a discharge tube and into the cooking reservoir.
U.S. patent application Ser. No. 11/621,226 of the present inventor discloses a portable liquid filter apparatus for filtering cooking oil in a container. The apparatus includes a mounting bracket that supports a pump and attaches to the container. A filter element is placed in the container for filtering the liquid. The pump draws the liquid through the filter element and a suction tube and discharges it back into the container for reuse. This apparatus permits the filtering of the cooking oil during the cooking operation.
U.S. Pat. No. 6,955,118 B1, issued on Oct. 18, 2005, to the present inventor describes a filter mounting apparatus that allows the filter to be removed for cleaning while the oil is still hot. The patent discloses a slip fitting mounted to the filter assembly and a receiver.